So what do you think? I don't have much experience with gdb. Getting a trace is about my limit. Does your xpp also panic instead of exiting normally after printing something? Mine does. See bug 214394. The trace I supplied with that one looks something like yours, but when I tried repeating it again just now I got something similar to the one I included here: lots of ??.
Do you have any ideas about what to do next?
Thanks,
Denver